[libc] Implement pkey_alloc/free/get/set/mprotect for x86_64 linux (#162362)

This patch provides definitions for `pkey_*` functions for linux x86_64.

`pkey_alloc`, `pkey_free`, and `pkey_mprotect` are simple syscall
wrappers. `pkey_set` and `pkey_get` modify architecture-specific
registers. The logic for these live in architecture specific
directories:

* `libc/src/sys/mman/linux/x86_64/pkey_common.h` has a real
implementation
* `libc/src/sys/mman/linux/generic/pkey_common.h` contains stubs that
just return `ENOSYS`.

3 files changed, 111 insertions, 1 deletions

diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index a27abbd5b386..bd48222856f2 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -6974,6 +6974,17 @@ libc_function(
     ],
 )
 
+libc_support_library(
+    name = "mprotect_common",
+    hdrs = ["src/sys/mman/linux/mprotect_common.h"],
+    deps = [
+        ":__support_common",
+        ":__support_error_or",
+        ":__support_osutil_syscall",
+        ":errno",
+    ],
+)
+
 libc_function(
     name = "mprotect",
     srcs = ["src/sys/mman/linux/mprotect.cpp"],
@@ -6982,6 +6993,7 @@ libc_function(
         ":__support_common",
         ":__support_osutil_syscall",
         ":errno",
+        ":mprotect_common",
     ],
 )
 
@@ -7041,6 +7053,85 @@ libc_function(
 )
 
 libc_function(
+    name = "pkey_alloc",
+    srcs = ["src/sys/mman/linux/pkey_alloc.cpp"],
+    hdrs = ["src/sys/mman/pkey_alloc.h"],
+    deps = [
+        ":__support_common",
+        ":__support_osutil_syscall",
+        ":errno",
+    ],
+)
+
+libc_function(
+    name = "pkey_free",
+    srcs = ["src/sys/mman/linux/pkey_free.cpp"],
+    hdrs = ["src/sys/mman/pkey_free.h"],
+    deps = [
+        ":__support_common",
+        ":__support_osutil_syscall",
+        ":errno",
+    ],
+)
+
+libc_function(
+    name = "pkey_get",
+    srcs = ["src/sys/mman/linux/pkey_get.cpp"],
+    hdrs = ["src/sys/mman/pkey_get.h"],
+    deps = [
+        ":__support_common",
+        ":__support_error_or",
+        ":__support_osutil_syscall",
+        ":errno",
+        ":pkey_common",
+    ],
+)
+
+libc_function(
+    name = "pkey_mprotect",
+    srcs = ["src/sys/mman/linux/pkey_mprotect.cpp"],
+    hdrs = ["src/sys/mman/pkey_mprotect.h"],
+    deps = [
+        ":__support_common",
+        ":__support_osutil_syscall",
+        ":errno",
+        ":mprotect",
+        ":mprotect_common",
+        ":types_size_t",
+    ],
+)
+
+libc_function(
+    name = "pkey_set",
+    srcs = ["src/sys/mman/linux/pkey_set.cpp"],
+    hdrs = ["src/sys/mman/pkey_set.h"],
+    deps = [
+        ":__support_common",
+        ":__support_error_or",
+        ":__support_osutil_syscall",
+        ":errno",
+        ":pkey_common",
+    ],
+)
+
+libc_support_library(
+    name = "pkey_common",
+    hdrs = [
+        "src/sys/mman/linux/pkey_common.h",
+    ] + selects.with_or({
+        PLATFORM_CPU_X86_64: ["src/sys/mman/linux/x86_64/pkey_common.h"],
+        "//conditions:default": ["src/sys/mman/linux/generic/pkey_common.h"],
+    }),
+    deps = [
+        ":__support_common",
+        ":__support_error_or",
+        ":__support_macros_properties_architectures",
+        ":hdr_errno_macros",
+        ":hdr_stdint_proxy",
+    ],
+)
+
+libc_function(
     name = "posix_madvise",
     srcs = ["src/sys/mman/linux/posix_madvise.cpp"],
     hdrs = ["src/sys/mman/posix_madvise.h"],
diff --git a/utils/bazel/llvm-project-overlay/libc/test/UnitTest/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/test/UnitTest/BUILD.bazel
index 522a2bd62db8..eb13ebd16a66 100644
--- a/utils/bazel/llvm-project-overlay/libc/test/UnitTest/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/test/UnitTest/BUILD.bazel
@@ -35,6 +35,7 @@ libc_test_library(
     srcs = [
         "BazelFilePath.cpp",
         "ExecuteFunctionUnix.cpp",
+        "LibcDeathTestExecutors.cpp",
         "LibcTest.cpp",
         "LibcTestMain.cpp",
     ],
diff --git a/utils/bazel/llvm-project-overlay/libc/test/src/sys/mman/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/test/src/sys/mman/BUILD.bazel
index 6de76e2357b7..845c6e70f3bd 100644
--- a/utils/bazel/llvm-project-overlay/libc/test/src/sys/mman/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/test/src/sys/mman/BUILD.bazel
@@ -2,7 +2,7 @@
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-# Tests for LLVM libc socket.h functions.
+# Tests for LLVM libc mman.h functions.
 
 load("//libc/test:libc_test_rules.bzl", "libc_test")
 
@@ -96,6 +96,24 @@ libc_test(
 )
 
 libc_test(
+    name = "pkey_test",
+    srcs = ["linux/pkey_test.cpp"],
+    deps = [
+        "//libc:hdr_errno_macros",
+        "//libc:hdr_signal_macros",
+        "//libc:mmap",
+        "//libc:munmap",
+        "//libc:pkey_alloc",
+        "//libc:pkey_free",
+        "//libc:pkey_get",
+        "//libc:pkey_mprotect",
+        "//libc:pkey_set",
+        "//libc:types_size_t",
+        "//libc/test/UnitTest:test_logger",
+    ],
+)
+
+libc_test(
     name = "posix_madvise_test",
     srcs = ["linux/posix_madvise_test.cpp"],
     deps = [